Halogen to led downlighters

[Wilson12]

Hello first floor has halogen recessed downlighters run off a 12v transformer.
I’m sure you can’t just swap the lamps to led but why is that if they both are low voltage and also
If it’s the first floor it needs to be fire rated right? Many thanks

 

[Wilson12]

Also why do some leds need a transformer and for downlighters and others all you need is the lamp

 

[SparkyChick]

It depends on the transformer as to whether it can be a straight swap. Some have minimum power demand requirements... so you might see a transformer rated 20-60w. Less than 20w and you're not guaranteed to get good quality output regulation (or even any output at all).

As for fire rating... it's not as simple as which floor it's on. If the house provides a single unit of occupancy for a single group of people, then none of the internal ceilings/walls are considered to be fire barriers. If the same property is split into two flats, ground floor and first floor, then the ceiling between the ground/first floors needs to be a fire barrier because whilst it is a single building, it's two distinct properties. I could be wrong with this and I'm sure someone will chip in if I am. The best plan for this is check building regulations, but I would ordinarily try and fit fire rated units where ever possible.

Why do some downlighters need a transformer and some just a lamp... because they have different supply voltages. GU10 LEDs have voltage regulators built into them and are supplied by 240v, MR16s don't and as such require a transformer to supply the 12v they need. This is somewhat overly simplified because most LED lamps have some form of regulation built in.

 

[Octopus]

To add: MR16 Leds do not always work with transformers - some have a minimum load ....... and the LED is below this.

As a trainee, don't you have a boss or a mentor?

 

[Wilson12]

Cheers

 

[Midwest]

To add my pennyworth to the fire rating thing; plasterboard as well as its aesthetic looks, also protects structures from fire, e.g. ceiling joists. And if the 18th has its way, plasterboard might prevent the return of the metal buckle clip.

Have a read of Wiring Matters 2005 14 Spring
Wiring Matters - 2005 issues - IET Electrical - https://electrical.------.org/wiring-matters/2005.cfm?

There was something a little bit more recent, which I'm unable to locate.

 

[Wilson12]

Last thing.
Old recessed light fittings for hologen gu10 if you take out the transformer.
The actual fitting itself that doesn’t matter if it’s being run on 230v does it sounds stupid

 

[SparkyChick]

Personally, I've not encountered a GU10 rated at anything other than 230v, but lets assume you have an old fitting that was for low voltage only. Before running it at 230v you need to be absolutely certain that the lamp holder and associated cabling/connections are suitably rated.